The objective of this study was to investigate the psychometric properties of a newly developed instrument for potentially traumatic life events, the Linköping Youth Life Experience Scale (LYLES), and determine the benefits of including adverse childhood circumstances (ACCs) as factors in the evaluation. In addition, we wanted to investigate the difference between interpersonal and noninterpersonal traumatic events, the impact of ACCs, and the cumulative effects of these events on self-reported symptoms of dissociation, depression, and anxiety. Adolescents from the normative population (n = 188) answered the questionnaire LYLES and also the Dissociation-Questionnaire-Sweden and Hospital Anxiety and Depression Scale. The results showed that LYLES was stable, with test-retest r = 0.79 and kappa item per item ranging between k = 0.44 and 1.0. ACCs contributed independently to the explanation of symptoms explaining them better than potentially traumatic events alone, particularly for boys where the impact of ACCs exceeded the impact of events. The conclusions are that LYLES displayed satisfactory psychometric properties and that ACCs seem to be a valuable addition to an instrument to evaluate potentially traumatic events.